Swashplate engine



Oct. 6, 1964 p. P. EASTMAN SWASHPLATE ENGINE 4 Sheets-Sheet 1 Filed Dec.2, 1960 Illil/l/l/l/l/l/ now INVENTOR. DAVID P. EASTMAN Oct. 6, 1964 n.P. EASTMAN SWASHPLATB ENGINE 4 Sheets-Sheet 2 INVENTOR. DAVID P EASTMANATT NEY x I 1/ i m? 2? Filed D60. 2, 1960 Oct. 6, 1964 o. P. EASTMAN3,151,528

SWASHPLATE ENGINE Filed Dec. 2, 1960 4 Sh ets-Sheet 3 so (Q) INVENTOR.

DAVID P. EASTMAN 2 F'IG.3 BY

AT ORNEY Oct. 6, 1964 D. P. EASTMAN SWASHPLATE ENGINE 4 Sheets-Sheet 4Filed Dec. 2, 1960 INVENTOR. DAVID P. EASTMAN %ORNEY United StatesPatent 3,151,528 SWASHPLATE ENGINE David P. Eastman, Novelty, Ohio,assignor to Clevite Corporation, a corporation of Ohio Filed Dec. 2,1960, Ser. No. 73,456 Claims. (Cl. 91175) This invention generallyrelates to an improvement in swashplate type engines and moreparticularly concerns static and dynamic balancing of such engines toreduce mechanical vibration.

A swashplate engine of the type herein referred to is disclosed incopending US. application Serial No. 60,- 746, filed October *5, 1960,which is assigned to the same assignee.

As used herein, a swashplate engine is taken to mean an engine having aplurality of pistons and cylinder assemblies with their stroke axisparallel to and symmetrically disposed to a power output shaft, thepistons coacting with an eccentric swashplate on the shaft so as toimpart rotary motion to the shaft in response to staggered linearreciprocation of the pistons in their respective cylinders. By virtue ofthis arrangement, and in order to construct an engine of this typecompatible with a vibration sensitive environment, it is necessary tocounterbalance the forces causing such vibration. Principally, we areconcerned with forces acting in three different directions. First, anaxially directed force produced by the reciprocating motion of thepistons and pants connected thereto. A centrifugal force exerted uponthe eccentric mass of the swashplate member, and a force created by theinertia of the reciprocating pistons. These three forces acting incombination are associated with the scquential orientation of theswashplate during the operation of the engine, and the rotation of theswashplate. All three forces change direction and in effect thus rotatewith the inner shaft. Rotation of these forces acting ultimately on thevehicle in which the engine is mounted, such as a torpedo, sets up avibration which influences the operating characteristics of the vehicle.

As aforestated the forces are not confined to a single plane ofexcitation and therefore produce what is known as a dynamic unbalance. Aforce which is confined to a single transverse plane normal to therotational axis, conventionally referred to as a static unbalancing, canbe counter-balanced only by a single weight placed with its massdiametrically opposite to the mass producing the force and lying in thesame plane therewith. On the other hand dynamic unbalance produces amoment or torque that can be suitably counter-acted only by another pairof forces acting oppositely to each other and lying in planes separatedby a substantial distance. It is for (this reason that the arrangementin accordance with the invention requires a first and a secondcounter-balancing weight which are spacedly secured with respect to eachother.

It is the primary object of this invention to provide a swashplateengine which is free of mechanical vibration, or in which such vibrationis minimized to an acceptable degree.

It is a further object of this invention to advantageously employcounter-balancing members for achieving the aforementioned objectivesand advantages.

To facilitate a better understanding of the present invention, togetherwith other and further objects thereof, reference is bad to thefollowing description taken in connection with the accompanyingdrawings, and its scope will be pointed out in the appended claims.

FIGURE 1 is a longitudinal partly sectional view through the aft sectionof a torpedo incorporating the invention;

3,151,528 Patented Got. 6, 1964 FIGURE 2 is a longitudinal partlysectional view through the swashplate engine taken along line 22 ofFIGURE 3;

FIGURE 3 is a front view of the engine spider member;

FIGURE 4 is a cross-sectional view of the spider member taken along line22 of FIGURE 3;

FIGURES 5 and 6 are enlarged side and end views of the conical valvemember;

FIGURE 7 is an exploded perspective view of major engine componentsincluding the forward counter-balancing member; and

FIGURE 7a is a sectional view of the latter member.

Introduction Referring now to the drawings and more particularly toFIGURE 1, there is illustrated a conventional afterbody 1 of a torpedoadapted to rotatably support swashplate engine 3. For ease ofdescription end 5 of the afterbody 1 is designated the forward sectionand end 7 the aft section. The swashplate engine 3 comprises a housing19 containing a fluid pressure responsive mechanism 145 (FIGURE 2) ofthe reciprocatory piston type, a rotatably mounted inner power take-offshaft 22 and a swashplate conversion assembly mounted to the inner shaft22 and connected to the fluid pressure responsive mechanism forconverting the reciprocatory substantially linear motion of the fluidpressure responsive mechanism 145 into rotary motion, transmitting therotary motion to the inner shaft 22 and simultaneously utilizing thetorque reaction caused by the reciprocatory movement of pistons 146 tocontra-rotate an outer second power takeoff shaft 16 which issubstantially integral with segments of the housing 10. A fluid pressuresupply tube 200 is connected to the housing 10 and is adapted tocooperate with a rotary valve 176 and related components hereinafterdescribed, which sequentially opens and closes flow communicationbetween the fluid pressure supply tube 200 and the fluid pressureresponsive mechanism 145 to effect a supply of fluid under pressure topiston heads 146 and to discharge the fluid after the same hasfunctioned to impart reciprocatory movement to the pistons. A forwardcounter-balancing sleeve 300 is secured to the inner power take-offshaft 22 immediately forward of the swashplate conversion assembly 95.An aft counter-balancing element 330 acting in conjunction with theforward counter-balancing sleeve is mounted to the inner shaft 22 at theaft end thereof and more particularly to a propeller mechanism assembly28.

Housing The housing as illustrated herein comprises a plurality ofindependent sections 12, 34, 44, 52 and 64 which are secured together toform the housing. The sections 12, 44 and 64 are connected by means ofbolts 13 arranged in circular array about the central axis of thehousing 10 and extending through sections 44 and 64 and into threadedengagement with section 12. The housing section 12 is formed of asemi-spherical hollow body or casing 14 and the integral outer or secondtubular power take-off shaft 16. The outer power take-off shaft 16 has acylindrical outer surface portion 18 adapted to provide a rotatablesupport means to carry a conventional propeller mechanism assembly 20,as partially shown in FIGURE 1. Outer power take-off shaft 16 is adaptedto receive radial load ball bearings 8, (9) to rotatably mount the shaftto the torpedo after-body. The hollow interior of the outer powertake-off shaft 16 is adapted to carry rotatably and coaxially the innertubular power take-off shaft 22. The inner shaft extends into the hollowhousing portion 14 and mates therein with conical valve member 176. Atthe opposite end the inner tubular shaft 22 extends beyond the axialextremity of the outer shaft 16 to provide a rotatable support 26 forcarrying coaxially a second propeller mechanism assembly 28. Theassembly 28 can thus be rotated independent of the first propellermechanism assembly 29.

With exceptions hereinafter noted, the first and second propellermechanism assemblies are composed of substantially identical materials.A blade 28a (29a) is integrally connected to a blade hub 28b (b), bothof such members are formed of conventional corrosion resistantmaterials.

The aft counter-balancing member 330 is an elongated rod, or substance,primarily comprised of a material having a higher specific weight thanthat from which the propeller assembly 28 is made.

The rod or substance for instance the latter being composed of lead, isinserted into a bore 332 drilled through the propeller hub 28b. SeeFIGURE 1. The bore 332 is positioned parallel to the central axis of theshaft, and arranged in this manner the aft counterbalancing memberprovides a center of mass positioned eccentrically with respect to therotational axis of the engine unit 3.

A metal cooling jacket 34, see FIGURE 2 and/or 3, is spaced around theengine casing 14 to provide a cooling water passage 36. Water conduits38 are suitably arranged in the casing as shown, to discharge thecoolant from the cooling passage as hereinafter further described. Thecooling jacket 34 is attached to the casing by means of suitable screws(not shown) and O-rings 4t) radially received in peripherally arrangedannular grooves 42 in the casing 14 engage the jacket 34 to preventwater leaks. The section 44 of the housing 10, see detail drawing FIG-URE 4, forms a cylindrical spider member, portions 46 of which arereceived in the hollow cylindrical casing housing 14, and opposite endsof spider member portions 48 are adapted to receive the hollowcylindrical housing section 52, which forms a cooling jacket and isarranged in the same manner as cooling jacket 34. The spider member isperipherally grooved to receive O-rings 48a and b which are adapted tosealingly engage the cooling jacket 52 and the casing member 12. Theconnection between members 44, 12 and 52 is conveniently accomplished bysuitably matching the diameter of the annular recess 50 or shoulder 51of each respective member, so as to register the cooling jacket 34 andthe casing member 12 to the spider member 44 with a press-fit.

The spider member 44 is formed with six openings 54, see FIGURE 3,positioned in circular array about the central axis of the spider, thecentral axis of each of the openings being substantially parallel to thecentral axis of hollow cylinders 56, see FIGURES 4 and 5. Each of suchspider openings 54 is adapted to rigidly receive an end portion 58 ofthe piston carrying cylinder 56. Each cylinder 56 is a hollowcylindrical casing and one axial end 58 of each cylinder is mounted tothe spider member as aforesaid, and the opposite end 62 is secured tohousing section 64 forming a circular engine head. To seal the cylinderinto position, an O-ring 40c is secured into an annular groove 410 ofthe engine head, and an O-ring 40d is secured into an annular groove 41din the spider member, the O-r-ings :being adapted to peripherallysurround the cylinder 56 at its respective ends. A central bore of thespider is adapted to suitably receive a tubular sleeve which has anannular recess 74 to receive and retain a graphitic annular seal 72. Theseal 72 is coaxially and rotatably mounted about rotary valve 176. Theforward end of the tubular sleeve 70 is formed with a plurality of slots76 and is mounted in an annular bore portion of the engine head 64. Thespider member 44 and the engine head 64 are thus spacedly connected andare further secured together by means of tubular cooling jacket 52 whichattaches to the respective ends of members 44, 64.

Internal Mechanism The inner tubular power take-off shaft 22 isrotatably and coaxially carried within the semi spherica-l hollow bodyportion 14 of casing 12 by means of a ball bearing assembly 86, of whichan annular outer race 88 is secured with a press-fit to an internalannular support shoulder 90 of the casing 12, and an inner annular race92 of the bearing 86 surrounds an annular sleeve 94 interposed betweenthe inner race 92 of the bearing and the shaft 22. The sleeve 94 has anoutwardly radially extending flange 96 which is adapted to take uplongitudinal thrust from a swashplate cam 93.

The swashplate cam 98 is rigidly secured to the inner shaft 22. Anannular ball bearing retaining ring 100 carried on the outer peripheralsurface 192 of the cam 98 provides a plurality of radially extendingopenings 104 adapted to receive in each opening a bearing ball 106. Anannular swashplate ring 112 is coaxially mounted to the bearingretaining ring 100. The bearing balls 106 ride in a ball bearing raceformed in the shape of an annular groove 108 in the swashplate cam andin a corresponding groove 110 provided in the annular ring 112. Theannular swashplate ring 112 is suitably connected to the reciprocatingpiston rods 148, as hereinafter further described, and the pistonsoperating in sequence force the swashplate ring 112 into wobble motioncausing a torque action on the swashplate cam 98 which is translated tothe inner power take-off shaft 22 causing it to rotate. Reaction to thepositive torque causes a negative torque reaction which effectscontra-rotation of the fluid pressure responsive mechanism 145 and allother components which are in fixed relationship to fluid pressureresponsive mechanism 145 such as housing 16, particularly note powertake-off shaft 16.

The swashplate cam 98 is secured to the inner shaft 22 by means of a key(not shown) fitting into key slot 120, and at the aft end the cam abutsagainst the radially outwardly extending flange 96 of the sleeve member94. At the forward end the cam is secured against a forward vibrationcounter-balancing member 300 of a generally annular form of which theend adjacent to the cam extends partially into an annular pocket 81 ofthe swashplate cam 98 to rigidly limit the axial freedom of the latter.The swashplate cam comprises essentially two annular sleeve portions 128and 130, which are integrally superimposed upon one another in arelationship permitting annular sleeve 128 to form a skew angle withrespect to the central axis of the cam, as is shown in FIG- URE 8. Thecylindrical outer surface of the sleeve 128 is eccentrically arrangedwith respect to the central axis of the cam 98 and provides a radialgroove 108 to receive partially therein bearing balls 106 which aredisposed to carry a combination thrust and radial load and convert thereciprocatory movement of the pistons 146 into rotary movement of theshaft 22. The ball retaining ring 100 is a substantially annular ringand is formed so as to permit an alignment of the axial center of eachaperture 194 with the corresponding axial center of the annular groove1%, 110 of the swashplate cam 98 and ring member 112, respectively.

The annular swashplate ring 112 is provided with six bores 134 arrangedin circular array about the central axis of the swashplate ring 112 toreceive and secure in each of such openings a bronze ball socket joint136, by means of which the ring 112 is connected to the reciprocatingpistons.

A circular face gear plate 138 is integrally arranged with the ring 112and its teeth 14%) are adapted to mesh with teeth 142 of the bevel gear143 mounted about the inner shaft and connected to the spider member 44by an annular flange portion 141 which extends into central bore 60 ofthe spider member. The engagement of the teeth of members 138 and 143serves to maintain the position of the swashplate ring in suitablerelationship with the outer housing 10 and the connecting rods 148.

The interaction of the gear teeth balances the forces imposed on theswashplate ring 112 by the fluid pressure responsive mechanism 145. Thegear meshing arrangement between bevel gear 1 -13 and gear plate 138 isof angular nature and while one segment of the gear teeth 140continuously meets with another segment of the gear teeth the oppositeend of such teeth are angularly removed from each other. The spacecreated thereby is advantageously utilized by securing between gears143, 138 the aforementioned forward counter-balancing member 300.

The counter-balancing member 300 is an annular sleeve upon which anannular region 304 of about 180 is peripherally superimposed. Thisregion 304 forms an cecentric mass with respect to the inner shaft withits center of mass substantially diametrically opposed to the center ofmass of the swashplate cam 98. A semi-cylindrical groove 306 in theannular region 304 extending substantially parallel with the outerperiphery thereof, facilitates machining of the sleeve 381) to providethe eccentric concentration of the mass in the region 304. An annularnut 308 with an inside thread 310 is fitted into opening 312 of thesleeve with a press-fit and at its aft end abuts against shoulder 314.The nut threadedly secures the sleeve to the inner shaft and against theswashplate cam 98. A spanner range fits into openings 389 of the nut toeffect a tight connection. An annular casing 316 is an integral part ofthe sleeve 300 and surrounds the inner shaft in a radially spacedrelationship. The casing 316 has a pair of radial flanges 318 (314)extending from the spaced portion to sealingly connect the casing to theinner shaft. A radial slot 320 in the casing is in a registeringposition with opening 322 in the shaft to which a vent tube 258 isinternally mounted, the vent tube extends radially from the openingtoward the central axis of the inner shaft, see FIGURE 2, the interiortube being thus positioned to enable fluid fiow between the interior ofthe hollow shaft and the hollow casing 12 through slot 320. Any coolant,described below present in the shaft 22 is prevented from rising orflowing into the casing while the shaft rotates, since the coolant iscentrifugally pressured in a radial direction whereby a free breathingzone is created near the axial center of the shaft, i.e., in theproximity of opening 259 of vent 258.

Essentially the fluid pressure responsive mechanism 145 comprises acylindrical piston 146 which is of suitable annular dimension to slidewithin the cylinder casing 56. The piston has an integrated socket joint149 receiving a spherelike end 150a of a piston rod member 148 whichconnects the piston 146 to the swashplate ring 112 by way of the ballend portion 150]; which is received in bronze ball socket joint 136. Thepiston may be formed of aluminum or other suitable material. As shown inFIGURE 8 the outer cylindrical surface 152 of the piston 146 has anumber of annular grooves of which grooves 154 and 156 each receive ametallic or plastic ring 162 therein, and groove 158 is adapted toreceive an O-ring 160. The O-ring 160 has a multiple function toperform, acting first as an oil control ring to wipe excess lubricantfrom cylinder wall as the piston descends to prevent lubricants frompenetrating into the fluid supply conduits and from coming into contactwith combustible gases. The O-ring 169 further serves to lend a certaindegree of radial resiliency to the reciprocating piston member 146. Theradial resiliency of the piston reduces frictional abrasion caused insome instances by deposition of solid combustion products in thecylinder casing 56. Radial resiliency of the O-ring 160 is alsoimportant in another aspect The piston head performs reciprocatorylinear motion during operation of the propulsion unit 3. However, sincethe central axis of the piston rods are not at all times parallel withrespect to the central axis of the device 3, the force of the pistonacting upon the connecting rods produces a slightly radial component offorce tending to push the piston against the cylinder wall. Anothersource of radial interference relates to the centrifugal action arisingfrom contra-rotation of the cylinder structure. Hence, the O-ringcarries at least a portion of this side burden and protects the metallicparts from frictional damage to pro vide proper sliding action of thepiston in the cylinder. A slight radial clearance is provided betweenthe inside diameter of the cylinder 56 and the outside diameter of thepiston, particularly at the location of the piston head. It may beadvantageous to use chemical fuel to produce the fluid under pressure inthe cylinders. In this event to reduce buildup of solids on the cylinderwalls it has been found advantageous to use metallic piston rings 162capable of lightly scraping the cylinder walls during the reciprocatorymotion.

Fluid Flow Control, and Passages Hot gas, or other suitable fluid, flowsfrom a combustion chamber, or equivalent (not shown), into a tubularconduit 164 and a hot gas seal assembly 166 and then enters into andthrough a rotary valve assembly 174. The rotary valve assembly 174comprises the rotary valve 176 and an annular conical seat 178 ofgraphitic or other suitable heat resistant material, secured in acylindrical pocket 188 of the engine head, and into which a conicalvalve head portion 182 of the valve 176 is partly inserted. The hot gasseal assembly 166 includes a sealing member 168 encased by an annularsteel sleeve 170, movable within a hot gas nozzle 172 to provide thefluid communication means between the hot gas supply chamber and thevalve 176.

The valve 176 has a conical valve head 182 and a tubular body portion184 extending coaxially from the conical head 182. The valve head 182 issubstantially hexagonal in cross-section, see FIGURES 2 and 5. Thisconfiguration avoids difficulties usually encountered with cylindricallyshaped valves, such as binding in the cylindrical seat as the valveexpands when the temperature increases. The angle across the conicalportion of head 189 adjacent to valve seat 178 is preferablyapproximately within the range of 55 to 65. An angle of 60 worksparticularly well. The double conical valve head as shown in FIG- URES2, 5 and 6 has the advantage of small surface contact and is preferredwhen particularly high temperatures are encountered. The outsidediameter of the tubular portion 184 is the same as the outside diameterof the inner shaft 22 and is adapted, by means of axially protrudingteeth 186, to mate with similarly protruding teeth 187 of the innershaft 22. The interlocking of these teeth establishes a connectionbetween the two members so that when the inner shaft 22 is caused torotate the conical valve 176 member rotates in unison with the shaft.The conical portion 182 of the valve 176, see FIGURE 2, is formed withinlet and outlet ports 188, 190. The ports provide, in conjunction withports 192, 194 which are formed in the valve seat and the engine headrespectively, a communicating passageway between the hot gas seal 166and the small chamber 191 in the engine head 64, and a flow connectionbetween the cylinders and the tubular portion 184 of the valve.

The sealing member 168 is substantially tubular and preferably made ofheat resistant material such as graphi-te. The stainless steel sleeve isin essence a protective casing around the sealing member. The seal andthe surrounding sleeve are tightly attached to each other and aremovable within tubular passageway 196 of nozzle 172 toward and away fromthe valve head 182. However, the sealing member 168 is limited in itsfreedom of rotary motion. The sealing member is keyed (not shown) to thehot gas nozzle by installing a pin in the wall of the hot gas nozzle,the pin projecting inwardly through the wall of the sealing member, arectangular slot is cut into the outer circumference of the sealingmember for engagement with the pin, the slot enables axial movement butprevents rotation. A spring member 198 concentrically surrounds a feedtube 200 within the passageway 196 of the hot gas nozzle, the spring 198is positioned to engage an internal annular shoulder 201 of the nozzleand reacts against an inwardly extending flange 262 portion of sleeve1'79, biasing the hot gas seal to maintain initial contact between thesealing members and the conical valve head. The feed tube 200 registerscoaxially with the central aperture 206 of the conical valve head. Asmall connecting tube 295 of suitable material is interposedtherebetween.

A hollow cylindrical bearing support member 2*38 spacedly surrounds thenozzle and one end thereof forms a radially outwardly extending flange212 mounted to the engine head. A radial load bearing 214 is mounted tothe outer surface 216 of bearing support member 208. The feed tube 2% iscooled by a cooling fluid which is introduced into the engine throughthe space 218 defined by the internal diameter of the bearing supportmember 208 and the circumference of the tubular nozzle. The nozzle hasan outwardly extending flange 222 which is provided with suitableapertures to secure the same either directly to the combustion chamber(not shown) or to other fluid communicating means.

In operation gas moves through the feed tube 200 and enters the inletport 188 of the valve 176. This port sequentially registers with one ofsix combination inlet and outlet ports 192, 194 distributed in circulararray around the central axis of the valve seat and the engine head, andleading to and from the cylinder head end 58. The gas drives the pistondownwardly in its cylinder and the gas is thereafter discharged throughports 192, 194 into passage 190 and into the hollow shaft portion 184 ofthe conical valve from which the exhaust gas is permitted to escapethrough the hollow shaft of the second or inner power take-off shaft 22.

The proper port selection takes place in accordance with a predeterminedcycle, which permits the single inlet passage 183 of the conical valveto be swept across each of the six cylinder ports 192 during onerevolution, and, further, the valve is so timed that fluid is admittedthrough the inlet ports 192 of the seat and the engine head port 194 toeach cylinder when the piston of the cylinder is approaching top deadcenter. The valve is also timed to close olf the passage to any onecylin der at an appropriate time in the piston cycle. Thus gas passage190 in the valve is arranged to register with the cylinder ports 192 sothat at the appropriate time in the cycle the port 194 to the cylinderis opened to the exhaust passage and the hot gas remaining in thecylinder, when the piston is above bottom dead center, is expelled fromthe cylinder through the outlet ports 194, 192, 190 respectively.

Preferably a coolant, such as water, is used for the preservation ofmetal parts which are subjected to high temperatures arising from thecombustion products. Such a coolant is introduced, see FIGURE 2, intothe device through the annular space 218 formed by sealing member 246surrounding the tubular hot gas nozzle 172. A face seal ring 250 securedto member 246 is provided to seal the water within space 218. Where theengine unit is adapted solely for uni-directional rotation the bearingsupport 208, as shown, may be utilized as part of the stationarystructure and can be joined to the hot gas nozzle 172. Water can then beintroduced to the annular space through an opening in the support 208with a fixed connection. The coolant then flows from the space 218through an annular space 219 located around the hot gas nozzle as shownin FIGURE 2, to an annular opening 252 circumscribed on one side by thebearing support member 208, and on the other side by rotary valve head182 and thereafter the coolant is directed to flow into annular pocket299.

A plurality of flow channels 68 are drilled into the engine head 64 todeliver the coolant entering annular pocket 299 to the forward and aftsection of the device. For forward section cooling the coolant flowsfrom channel 68 into and through narrow slots 69 provided in acylindrical ring 71 to deflect the coolant onto cylinder 58, theremainder flowing to cooling jacket space 66 bounded by cooling jacket52. The tubular sleeve 70 surrounding the tubular stem 184 of the rotaryvalve, forms the inner boundary for the water jacket space 66. The slots'76 of the tubular sleeve, aforedescribed, are provided as a dischargeopening for water leaving the space 66. Thus the coolant enters throughthe slot 76 and passes through the annular space 78 surround ing thevalve stem from which point the coolant is free to flow into the tubularinterior of the rotary valve by passing through apertures 81 provided inthe stem portion 184 of the valve.

For aft section cooling, a channel not shown, connects the annularpocket 209 of the supporting member 208 to annular pockets 211surrounding portions of bolts 13. The annular pocket 211 is drilled fromthe aft end into the engine head and O-rings 225 disposed within annularpockets 211 about bolts 13 prevent coolant from penetrating into thespace 66. The annular pockets are in flow communication with radialbores 15a of the bolts. The bores 15a communciate flow from pockets 211to radial bores 15c drilled in the casing 12, by means of intermediatebores 15b drilled through part of the central axes of the bolts 13.Thus, the coolant flows along the axes of the bolts through bores intocooling jacket space 36 bounded by jacket 34. From space 36 the coolantis fed through passageways 38 and finally through radial apertures 213into inner power take-off shaft 22. Two annular seals 215, 217 aremounted about the shaft 22 oppositely adjacent to apertures 213.

Once the coolant is in the hollow confines of the tubular stem of theinner power take-off shaft, the coolant joins the exhaust gas where itserves the function of cooling the exhaust for the protection of enginecomponents along the exhaust path. In instances where the fluid is of anature producing extremely high temperatures, the valve head is partlycooled by channeling a portion of the coolant from space 219 throughaxial channel 253 in the rotary valve head 182. The channel 253 thusprovides for cooling the interior of the valve head and establishes flowcommunication between space 219 and inner shaft 22, the latter alsopermits gases which may have escaped the hot gas seal to be expelledthrough the channel.

The coolant is expelled through shaft 22 either directly out into theopen or into and through specially adapted discharge lines which are notillustrated in the drawings.

Cooling is also effected by efficient utilization of lubricants incasing 12. By action of the swashplate and the reciprocating motion ofthe pistons, the lubricant is rapidly turned within the cylindrical bodyportion 14 and forced in and out of the open ends of the cylinders 58.In operation, the rapid movement of lubricant brings it alternatively incontact with the exposed surfaces of the pistons 146 and the socketjoints 136 whereby considerable heat is removed by contact. To retainthe lubricant within casing 12 a lubricant seal 254 is disposed inannular pocket 256 of spider member 48. To prevent clogging of the venttube 253 by the lubricant and loss of lubricant, the forward vibrationcounter-balancing member and more particularly the annular casing 316,aforedescribed, co-acts with vent tube 258 permitting only gas, such asmay have accumulated in the casing through leakages, to escape throughthe vent. The arrangement, by means of centrifugal and accelerativeforces, causes the gas to separate from the lubricant and the latter isthrown back into the casing.

A vent tube 260 similar to tube 258 is positioned in the inner shaft ata location further aft. Vent 260 maintains the annular space betweeninner and outer shaft at exhaust pressure and channel 262 drilledthrough the outer shaft 16 communicates the pressure with externalareas. An annular seal unit 264 is arranged with a bronze 9 retainer264a and O-rings 264k for sealing between the inner and outer shaft toprevent foreign substances to enter into the casing 12.

While there have been described what at present are considered to be thepreferred embodiments of this invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is aimed,therefore, in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of the invention.

I claim as my invention:

1. A swashplate engine comprising, in combination: a rotatably mountedcylinder housing member having a plurality of cylinder bores extendingparallel to and being arranged in circular array about the central axisof the member; piston means slidably disposed for reciprocation in eachcylinder bore; a power take-off shaft coaxially and rotatably mountedwith respect to said housing; swashplate means secured to said shaft andoperatively associated with the reciprocable piston means to convert thereciprocatory motion into an angular force component and to exert thelatter upon said shaft to rotate the shaft in one direction and causingsaid housing member to be rotated in the opposite direction; fluidsupply and exhaust conduits in said housing member connecting each ofsaid cylinder bores to a fluid fuel source; a rotatably mounted valve incoaxial engagement with said shaft and rotatable in unison therewith tosequentially open and close fluid flow communication between saidconduits and said cylinder bores; and a first and secondcounter-balancing means connected to said shaft having a center of massdisposed eccentrically to the axis of rotation of said shaft, said firstcounter-balancing means being axially spaced with respect to said secondcounterbalancing means and, in combination, said first and secondbalancing means having centers of mass diametrically opposite to thecenter of mass of the swashplate means.

2. A swashplate engine comprising, in combination: a rotatably mountedcylinder housing member having a plurality of cylinder bores extendingparallel to and being arranged in circular array about the central axisof the member; piston means slidably disposed for reciprocation in eachcylinder bore; a power take-off shaft coaxially and rotatably mountedwith respect to said housing; swashplate means secured to said shaft andoperatively associated with the reciprocable piston means to convert thereciprocatory motion into an angular force component and to exert thelatter upon said shaft to rotate the shaft in one direction and causingsaid housing member to be rotated in the opposite direction; fluidsupply and exhaust conduits in said housing member connecting each ofsaid cylinder bores to a fluid fuel source; a rotatably mounted valve incoaxial engagement with said shaft and rotatable in unison therewith tosequentially open and close fluid flow communication between saidconduits and said cylinder bores; a first dynamic balancing meansaxially disposed about said shaft and formed of an annular sleeve havingan eccentric peripheral portion; means mounting said balancing means tosaid shaft; and a second dynamic balancing means connected to said shaftand having a center of mass disposed eccentrically to the axis ofrotation of said shaft and axially spaced with respect to said eccentricperipheral portion of said first balancing means.

3. A swashplate engine comprising, in combination: a rotatably mountedcylinder housing member having a plurality of cylinder bores extendingparallel to and being arranged in circular array about the central axisof the member; piston means slidably disposed for reciprocation in eachcylinder bore; a power take-off shaft coaxially and rotatably mountedwith respect to said housing; swashplate means secured to said shaft andoperatively asso ciated with the reciprocable piston means to convertthe reciprocatory motion into an angular force component and to exertthe latter upon said shaft to rotate the shaft in one direction andcausing said housing member to be rotated in the opposite direction;fluid supply and exhaust conduits in said housing member connecting eachof said cylinder bores to a fluid fuel source; a rotatably mounted valvein coaxial engagement with said shaft and rotatable in unison therewithto sequentially open and close fluid flow communication between saidconduits and said cylinder bores; a first and second propeller hub, saidfirst propeller hub being connected to said housing member, and saidsecond propeller hub being coaxilly mounted to said shaft; a portion ofsaid second hub arranged eccentric relative to the axis of said shaftand formed of a material having a specific weight higher than themajority of the remainder material forming said hub; and a dynamicbalancing means connected to said shaft and having a center of massdisposed eccentrically to the axis of rotation of said shaft and spacedrelative to said portion of said hub.

4. A swashplate engine comprising, in combination: a rotatably mountedcylinder housing member having a plurality of cylinder bores extendingparallel to and being arranged in circular array about the central axisof the member; piston means slidably disposed for reciprocation in eachcylinder bore; a power take-off shaft coaxially and rotatably mountedwith respect to said housing; swashplate means secured to said shaft andoperatively associated with the reciprocable piston means to convert thereciprocatory motion into an angular force component and to exert thelatter upon said shaft to rotate the shaft in one direction and causingsaid housing member to be rotated in the opposite direction; fluidsupply and exhaust conduits in said housing member connecting each ofsaid cylinder bores to a fluid fuel source; a rotatably mounted valve incoaxial engagement with said shaft and rotatable in unison therewith tosequentially open and close fluid flow communication between saidconduits and said cylinder bores; an annular sleeve mounted about saidshaft, said sleeve having an annular region superimposed upon portionsof the sleeves radial periphery forming an eccentric mass with respectto said shaft; an annular casing integral with said sleeve and partlyradially spaced with respect to said shaft, said casing having a pair ofradial flanges connecting the radially spaced casing to said shaft; aradial slot in said casing, one of said flanges being axially forwardand another being axially rearward of said slot; means securing saidsleeve to said shaft; a vent tube mounted to said shaft and extendingtoward the axial center of the shaft; said shaft having a radiallyextending fluid passageway proximate to said slot; and a dynamicbalancing means connected to said shaft and having a center of massdisposed eccentrically to the axis of rotation of said shaft and spacedrelative to said sleeve.

5. A swashplate engine comprising, in combination: a rotatably mountedcylinder housing member having a plurality of cylinder bores extendingparralel to and being arranged in circular array about the central axisof the mem ber; piston means slidably disposed for reciprocation in eachcylinder bore; a power tak-ofr shaft coaxially and rotatably mountedwith respect to said housing; swashplate means secured to said shaft andoperatively asso ciated with the reciprocable piston means to convertthe reciprocatory motion into an angular force component and to exertthe latter upon said shaft to rotate the shaft in one direction andcausing said housing member to be rotated in the opposite direction;fluid supply and exhaust conduits in said housing member connecting eachof said cylinder bores to a fluid fuel source; a rotatably mounted valvein coaxial engagement with said shaft and rotatable in unison therewithto sequentially open and close fluid flow communication between saidconduits and said cylinder bores; an annular sleeve mounted to saidshaft, said sleeve having an annular region super- 1 1 imposed uponportions of the sleeves radial periphery forming an eccentric mass withrespect to said shaft; an annular casing integral with said sleeve andpartly radially spaced with respect to said shaft, said casing having apair of radial flanges connecting the radially spaced casing to theshaft; a radial slot in said casing, one of said flanges being axiallyforward and the other being axially rearward of said slot; meanssecuring said sleeve to said shaft; a vent tuoe mounted to the shaft andextending toward the axial center of the shaft; said shaft having aradially extending fluid passageway proximate to said slot; 21 first andsecond propeller hub, said first propeller hub being connected to saidhousing means, and said second propeller hub being coaxially mounted tosaid shaft; and a portion of said hub arranged eccentric relative tosaid axis of said shaft and formed of a material having a specificweight higher than the majority of the remainder material forming saidhub and spaced relative to said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS355,814 Esty Jan. 11, 1887 630,767 Beadle Aug. 8, 1899 1,152,004 CantonAug. 31, 1915 1,378,855 Gollings May 24, 1921 1,885,323 Duryea Nov. 1,1932 2,097,138 Steele Oct. 26, 1937 2,713,829 Bwcham July 26, 19552,964,234 Loomis Dec. 13, 1960 FOREIGN PATENTS 137,552 Great BritainJan. 22, 1920

1. A SWASHPLATE ENGINE COMPRISING, IN COMBINATION: A ROTATABLY MOUNTEDCYLINDER HOUSING MEMBER HAVING A PLURALITY OF CYLINDER BORES EXTENDINGPARALLEL TO AND BEING ARRANGED IN CIRCULAR ARRAY ABOUT THE CENTRAL AXISOF THE MEMBER; PISTON MEANS SLIDABLY DISPOSED FOR RECIPROCATION IN EACHCYLINDER BORE; A POWER TAKE-OFF SHAFT COAXIALLY AND ROTATABLY MOUNTEDWITH RESPECT TO SAID HOUSING; SWASHPLATE MEANS SECURED TO SAID SHAFT ANDOPERATIVELY ASSOCIATED WITH THE RECIPROCABLE PISTON MEANS TO CONVERT THERECIPROCATORY MOTION INTO AN ANGULAR FORCE COMPONENT AND TO EXERT THELATTER UPON SAID SHAFT TO ROTATE THE SHAFT IN ONE DIRECTION AND CAUSINGSAID HOUSING MEMBER TO BE ROTATED IN THE OPPOSITE DIRECTION; FLUIDSUPPLY AND EXHAUST CONDUITS IN SAID HOUSING MEMBER CONNECTING EACH OFSAID CYLINDER BORES TO A FLUID FUEL SOURCE; A ROTATABLY MOUNTED VALVE INCOAXIAL ENGAGEMENT WITH SAID SHAFT AND ROTATABLE IN UNISON THEREWITH TOSEQUENTIALLY OPEN AND CLOSE FLUID FLOW COMMUNICATION BETWEEN SAIDCONDUITS AND SAID CYLINDER BORES; AND A FIRST AND SECONDCOUNTER-BALANCING MEANS CONNECTED TO SAID SHAFT HAVING A CENTER OF MASSDISPOSED ECCENTRICALLY TO THE AXIS OF ROTATION OF SAID SHAFT, SAID FIRSTCOUNTER-BALANCING MEANS BEING AXIALLY SPACED WITH RESPECT TO SAID SECONDCOUNTERBALANCING MEANS AND, IN COMBINATION, SAID FIRST AND SECONDBALANCING MEANS HAVING CENTERS OF MASS DIAMETRICALLY OPPOSITE TO THECENTER OF MASS OF THE SWASHPLATE MEANS.